在webroot子目录下的jsp<form>表单怎么到servlet?

  <form action="../../ProjectUpload"  method="post">

</form>

注意 要在web.xml中配置

<servlet>
<servlet-name>ProjectUpload</servlet-name>
<servlet-class>com.njit.action.ProjectUpload</servlet-class>
</servlet>

<servlet-mapping>
<servlet-name>ProjectUpload</servlet-name>
<url-pattern>/ProjectUpload</url-pattern>
</servlet-mapping>